Packaging machine

ABSTRACT

A product packaging machine comprises a conveyor ( 4 ) for feeding the products along an axis (D) in a feed direction (V); a grouping station ( 5 ) for the products ( 3 ) located downstream of the conveyor ( 4 ) along the feed direction (V) for grouping the products ( 3 ) into a group ( 2 ) of products ( 3 ); the group ( 2 ) has at least a first and a second layer ( 6, 7 ) of products ( 3 ); at the grouping station ( 5 ), the machine ( 1 ) comprises stacking means ( 11 ), by which at least the first and the second layer ( 6, 7 ) are stacked from the bottom up; more specifically, the stacking means ( 11 ) raise the first layer ( 6 ) from the bottom up and stack the second layer ( 7 ) from below, under the first layer ( 6 ).

BACKGROUND OF THE INVENTION

This invention relates to a packaging machine and, more specifically, to a machine known as “cartoner” for packing loose products into cartons or boxes.

In the state of the art, packaging machines of this kind comprise a first product feed line, at the end of which the products are suitably arranged in groups composed of two or more superposed layers, each layer being composed of a plurality of aligned products.

Downstream of the first product feed line there is normally a second line, known as “cartoner”, usually located at right angles to the first line, along which the products are packed into respective boxes or cartons, for example of cardboard.

More specifically, along the second line, a carton blank is folded around the group of products to form the carton containing the products themselves.

Alternatively, the groups are inserted into preformed cartons which are first opened by an operation known as “squaring” to form a tubular structure into which the group of products is inserted. The cartons are then folded at the ends in order to close them.

To form the groups of products to be inserted into the cartons, the prior art solutions comprise a lift/lower system by which a layer of products is placed on top of the one preceding it. In practice, a conveyor belt feeds a first layer of products onto a lift/lower surface which is movable vertically downwards.

The lift/lower surface is lowered and the conveyor belt feeds a second layer onto the first. This procedure is repeated for all the layers to form the aforementioned group.

Once the group of layers is formed, a pusher urges the group onto the second line, where the group is packed into a carton.

The lift/lower system of prior art packaging machines has some disadvantages.

A first disadvantage is due to the fact that the lift/lower system is slow compared to the other parts of the packaging machine whose performance is thus reduced.

Also, the lift/lower system is not versatile in that its up/down stroke is fixed as a function of the expected height of the group of products to be cartoned.

SUMMARY OF THE INVENTION

In this context, the main technical purpose of this invention is to propose a packaging machine which is free of the above mentioned disadvantages.

This invention has for an aim to provide a packaging machine that is faster than prior art machines.

Another aim of this invention is to provide a packaging machine which is more versatile than prior art machines and that is to say, more specifically, a machine which can pass from handling products or groups of products of one size to products or groups of products of another size without problems.

In other words, one aim of the invention is to provide a packaging machine which facilitates changeover operations.

The technical purpose and aims specified are substantially achieved by a product packaging machine according to claim 1 and a product packaging method according to claim 9.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the invention and its advantages are more apparent in the non-limiting description below, with reference to a preferred but non-exclusive embodiment of a packaging machine, as illustrated in the accompanying drawings, in which:

FIGS. 1 to 6 are schematic perspective views, with some parts cut away for greater clarity, of a packaging machine according to this invention in a sequence of operating steps;

FIGS. 7 to 8 are schematic front views of a detail of the packaging machine according to the invention in a sequence of operating steps.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the numeral 1 denotes a packaging machine according to this invention.

The machine 1 is of the type known as “cartoner” designed to package groups 2 of products 3 into a respective pack 9.

More specifically, the products 3 are containers, preferably for toothpaste tubes, not illustrated.

The machine 1 comprises a conveyor 4 for feeding the products 3 in sequence along an axis D in a feed direction V and a grouping station 5 for the products 3 located downstream of the conveyor 4 along the feed direction V.

The conveyor 4 is in the form of a conveyor belt trained around a drive roller and a driven roller.

At the grouping station 5, the products 3 are grouped into a group 2 comprising at least a first and a second layer 6 and 7 of products 3.

More specifically, each layer 6, 7 comprises one or more of the products 3.

The first and the second layer 6 and 7 have respective flanks 20, an underside face 25 and a top face 10.

In the embodiment illustrated by way of example, the group 2 of products 3 is made up of four layers 6, 7, each of which is defined by six products 3 placed side by side.

Downstream of the grouping station 5, there is a packaging station 23.

At the packaging station 23, the machine 1 comprises means 8 for packing each group 2 of products 3.

The packing means 8 are located downstream of the grouping station 5 along the feed direction V to package the group 2 of products 3 into the respective pack 9.

Preferably, the pack 9 is obtained from a pre-weakened flat blank which is folded in customary manner around the group 2 of products 3.

In an alternative embodiment, the pack 9 is obtained by “squaring” or opening pre-formed containers.

At the grouping station 5, the machine 1 comprises stacking means 11, by which at least the first and the second layer 6 and 7 are stacked from the bottom up.

In other words, the stacking means 11 stack the layers 6, 7 of the groups 2 of products from the bottom up by placing the first layer 6, or top layer, and then placing the second layer 7, or bottom layer, under it.

In other words, the stacking means 11 are adapted to stack one layer 6, received later, under one or more layers 6, 7, received earlier, to form the required group 2 of products 3 relative to a stacking axis A.

In the embodiment described, the stacking axis A extends vertically at right angles to the feed axis D of the products 3.

The stacking means 11 comprise a first and a second pair 26, 27 of arms 15, 16, located on opposite sides of the stacking axis A and each comprising at least a first and a second arm 15, 16.

The first and the second arm 15, 16 of each pair 26, 27 are connected to a single hinge C1 located at the same first end 15 a, 16 a of the first and the second arm 15, 16.

The first and the second arm 15, 16 of each pair 26, 27 comprise a respective first and second profiled section 14 a, 14 b for supporting the first and second layers 6, 7 of products 3, each connected by means of a respective second hinge C2 at a respective second end 15 b, 16 b of the first and the second arm 15, 16, opposite the first end 15 a, 16 a.

The second hinge C2 of each first and second profiled section 14 a, 14 b allows the first and the second profiled section 14 a, 14 b to rotate independently of the rotation of the arms 15, 16 about the first hinge (C1).

The first and the second profiled section 14 a, 14 b of each pair 26, 27 of arms 15, 16 rotates about the respective second hinge C2 in a direction of rotation opposite to the direction of rotation of the respective first and second arm 15, 16 about the first hinge C1.

The first and the second profiled section 14 a, 14 b of each pair 26, 27 of arms 15, 16 rotates about the second hinge C2 simultaneously with the rotation of the first and second arm 15, 16 about the respective first hinge C1.

The first and second profiled sections 14 a, 14 b define respective pairs 14 of profiled sections.

The stacking means 11 comprise at least first and second retaining elements 12 and 13.

The first arm 15 and the first profiled section 14 a and the second arm 16 and the second profiled section 14 b of each pair 26, 27 constitute first and second retaining elements 12, 13.

The first profiled section 14 a and the second profiled section 14 b extend mainly along an axis parallel to the feed axis D of the products 3.

Advantageously, the products 3 are fed along the first profiled section 14 a and the second profiled section 14 b along an axis parallel to the feed axis D of the products 3.

Each profiled section 14 a, 14 b has a cross section which is preferably in the shape of an “L”, along an axis transversal to the feed axis D of the products 3, so as to act as a lateral guide during the translational movement of the products 3.

Each profiled section 14 a, 14 b comprises a respective flat supporting surface 17 and a respective side wall 18.

The flat supporting surface 17 and the side wall 18 are contiguous to each other and define the cross section of the profiled section, and more specifically, the L-shaped cross section, transversal to the feed axis D.

The flat supporting surface 17 is designed to come into contact with a portion of the underside face 25 of a respective layer 6, 7 of products 3.

Advantageously, the flat supporting surface 17 remains parallel to the underside contact face 25 of the layers 6, 7 of products 3 while the layers 6, 7 of products 3 are being stacked relative to the stacking axis A.

The side wall 18 is designed to come into contact with one of the flanks 20 of a respective layer 6, 7 of products 3.

The stacking means 11 rotate about the first and the second hinge C1, C2.

More precisely, the first and the second profiled section 14 a and 14 b of each pair 14 of the first and second retaining elements 12 and 13 rotate about the respective second hinge C2.

The hinges C1 and C2 define respective parallel axes of rotation, and in particular, parallel to the feed axis D.

More specifically, the first and the second arm 15 and 16 are connected, respectively, to the first and the second profiled section 14 a and 14 b by means of the second hinge C2 and are hinged to each other at the first hinge C1.

Advantageously, the first and second arms 15, 16 of the first and second retaining elements 12 and 13 are hinged to each other and rotate about the same hinge C1.

The first and second retaining elements 12 and 13 move alternately from a first operating position for retaining one of either the first or the second layer 6, 7 of products 3 to a second operating position for retaining one or more layers 6, 7 of products 3.

In moving from the first to the second operating position, the first and the second retaining elements 12 and 13 raise one of either the first or the second layer 6 or 7 from the bottom up.

More specifically, at the first operating position, one of either the first or the second layer 6, 7 of products 3 is supported on one of either the first or the second retaining element 12, 13.

At the second operating position, two or more layers 6, 7 of products 3 are supported in the raised position until the group 2 of products 3 is formed.

Once the group 2 of products 3 is formed, this group is unloaded from the stacking means 11 at the second operating position of the first and second retaining elements 12 and 13.

The first and second retaining elements 12 and 13 are synchronized with each other in such a way that the first retaining elements 12 move from the first to the second operating position when the second retaining elements 13 move from the second to the first operating position, and vice versa.

From the first to the second operating position, and vice versa, the first and second retaining elements 12, 13 rotate about the first and the second axis of rotation 11 a and 11 b by a respective quantity equal to the size of the angle of rotation.

More specifically, in order to produce the alternating movement of the first and second retaining elements 12 and 13 from the first to the second operating position and from the second to the first operating position, the size of the angle of rotation of the first retaining elements 12 is different from the size of the angle of rotation of the second retaining elements 13.

More precisely, to move from the first to the second operating position, the first or the second retaining elements 12, 13 rotate by a quantity equal to the size of a first angle of rotation α1.

More specifically, the first and the second arm 15, 16 of each pair 26, 27 rotate about the first hinge C1 by a respective quantity equal to the size of the angle of rotation α1, α2.

From the first to the second operating position, and vice versa, the size of the angle of rotation α1, α2 of the first arm 15 is different from the size of the angle of rotation α1, α2 of the second arm 16.

To move from the second to the first operating position, the first or the second arms 15, 16 rotate by a quantity equal to the size of a second angle of rotation α2, greater than the first angle of rotation α1.

Since the first and second retaining elements 12 and 13 are synchronized in such a way that when the first retaining elements 12 move from the first to the second operating position, the second retaining elements 13 move from the second to the first operating position, and vice versa, it follows that if the first arms 15 rotate by a quantity equal to the size of a first angle α1, the second arms 16 rotate by a quantity equal to the size of a second angle α2 of rotation, and vice versa.

In use, the conveyor 4 feeds the products 3 along the axis D in a feed direction V.

Preferably, the products 3 transported by the conveyor 4 are pre-grouped in a row along the feed axis D.

In the embodiment illustrated by way of example, the products 3 transported by the conveyor 4 are pre-grouped in a row by three along the feed axis D.

Alternatively, the products 3 are transported individually by the conveyor 4.

At the grouping station 5, a first pusher 21 transfers the products 3 transported by the conveyor 4 onto the stacking means 11. More specifically, the products 3 are transferred onto the first retaining elements 12 which are positioned at their first operating position, as illustrated in FIG. 1.

More precisely, the products 3 move translationally along the flat supporting surface 17 of the first profiled section 14 a of the first retaining elements 12.

The products 3 are loaded onto the first retaining elements 12 until the first layer 6 of products 3 is formed.

In this embodiment, the first and the second layer 6, 7 of products 3 comprise six products 3 and are formed when two rows of three products 3 each are transferred onto the stacking means 11.

It should be noted that, advantageously, there is a gap 22 between the flanks 20 of the first layer 6 of products 3 and the side walls 18 of the first profiled section 14 a of the first retaining elements 12.

The gap 22 prevents the products 3 from getting wedged as they move along the profiled sections 14 a, 14 b of the stacking means 11.

Once the first layer 6 of products 3 is loaded onto the first retaining elements 12, the latter move from the first operating position to the second operating position, lifting the first layer 6 of products 3 from the bottom up, as illustrated in FIG. 2.

During the movement from the first operating position to the second operating position, the first arms 15 rotate simultaneously about the first hinge C1.

More specifically, the first arms 15 rotate about the first hinge C1 by a quantity equal to the size of a first angle of rotation α1.

During the rotation of the first arms 15, the respective first profiled sections 14 a rotate about the respective second hinge C2 in a direction of rotation opposite to that of the first arms 15. Advantageously, the rotation of the profiled sections 14 a, 14 b in the opposite direction to that of the arms 15, 16 allows best use to be made of the flat supporting surface 17 of the profiled sections 14 a, 14 b, maximizing the available surface area of the flat supporting surface 17.

In effect, thanks to the opposite rotation about the second hinge C2, the distance between the first profiled sections 14 a of the first retaining elements 12, measured transversely to the feed axis D, diminishes until the side walls 18 of the first profiled sections 14 a come into abutment against the flanks 20 of the first layer 6 of products 3.

In other words, the first profiled sections 14 a of the first retaining elements 12 move closer together by a quantity substantially equal to the gap 22.

When the side walls 18 of the first profiled section 14 a are in contact with the flanks 20 of the first layer 6 of products 3, the first profiled sections 14 a of the first retaining elements 12 are positioned at a minimum distance from each other, measured transversely to the feed axis D.

As the first arms 15 continue to rotate about the first hinge and the first profiled sections 14 a continue to rotate about the respective second hinges C2, the first profiled sections 14 a of the first retaining elements 12 move apart, away from the position where they are at the minimum distance from each other. On reaching the second operating position, the first retaining elements 12 hold the first layer 6 of products 3 in the raised position, while the second retaining elements 13 are positioned at the first operating position to form the second layer 7 of products 3, as illustrated in FIGS. 3 and 7.

During the formation of the layers 6, 7 of products 3, both the first and the second retaining elements 12 and 13 remain stationary at their respective positions.

In this case, while the second layer 7 of products 3 is being formed on the second retaining elements 13, the first retaining elements 12 hold the first layer 6 of products 3 in the raised position.

In other words, the stacking means 11 raise the first layer 6 from the bottom up and place the second layer 7 under the first layer 6, from below.

It should be noted that for the formation of the second layer 7 of products 3 on the second retaining elements 13 and for the movement of the second retaining elements 13 from the first to the second operating position, the same considerations made above in connection with the first retaining elements 12 also apply to the second arms 16 and the second profiled sections 14 b.

In effect, once the second layer 7 of products 3 is formed on the second retaining elements 13, the latter move from the first operating position to the second operating position, lifting the second layer 7 of products 3 from the bottom up.

During the movement from the first operating position to the second operating position, the second arms 16 rotate about the first hinge C1.

More specifically, the second arms 16 rotate about the first hinge C1 by a quantity equal to the size of the first angle of rotation α1.

Simultaneously with the movement of the second retaining elements 13 from the first to the second operating position, the first retaining elements 12 move from the second to the first operating position.

More specifically, the first arms 15 rotate respectively and simultaneously about the first hinge C1 by a quantity equal to the size of the second angle of rotation α2.

During the rotation of the first arms 15 about the first hinge C1, the distance between the profiled sections 14 a of the first retaining elements 12, measured transversely to the feed axis D, increases until the flat supporting surfaces 17 of the first profiled sections 14 a slide out from under the first layer 6 of products 3, releasing it on the second layer 7 of products 3, supported by the second retaining elements 13, as illustrated in FIGS. 4 and 8.

It should be noted that as the first and second profiled sections 14 a, 14 b move towards and away from each other, they maintain their positions in the sense that the respective flat supporting surfaces 17 remain parallel to the underside contact face 25 of the layers 6, 7 of products 3 relative to the stacking axis A.

That is because the first and the second profiled section 14 a, 14 b of each pair 26, 27 of arms 15, 16 rotates about the second hinge C2 in a direction of rotation opposite to the direction of rotation of the respective first and second arms 15, 16 about the first hinge C1.

It should be noted that, advantageously, the first layer 6 of products 3 is released onto the second layer 7 of products 3 when the second profiled sections 14 b of the second retaining elements 13 are at a minimum distance from each other, measured transversely to the feed axis D, and their side walls 18 are in contact with the flanks 20 of the second layer 7.

That way, the base of the layers 6, 7 to be stacked—in this particular case, of the second layer 7—is stable.

The stacking of the layers 6, 7 actually occurs during the movement from the first to the second operating position of one of either the first or the second retaining elements 12 or 13 and movement from the second to the first operating position of the other of either the first or the second retaining elements 12 or 13.

Once the first layer 6 is released onto the second layer 7, the first retaining elements 12 continue rotating about the first hinge C1 towards the first operating position and, simultaneously, the second retaining elements 13 continue rotating about the first hinge C1 towards the second operating position.

At this point, the second profiled sections 14 b keep the first and second layers 6 and 7, now stacked on each other, in the raised position.

It should be noted that if the group 2 of products 3 is composed of more than two layers 6, 7, the stacking means 11 continue stacking layers 6, 7 until reaching the required number of layers.

More specifically, the first and second retaining elements 12 and 13 sequentially repeat the movements from the first to the second operating position, and vice versa, as a function of the number of layers 6, 7 to be stacked.

It should be noted that during the movement from the first to the second operating position of the second retaining elements 13, the same considerations apply as those made above in connection with the first retaining elements 12.

More specifically, the second arms 16 rotate about the first hinge C1 by a quantity equal to the size of the second angle of rotation α2.

Since the stacking means 11 work from the bottom up, at least one pair of guides 24 is provided along the flanks of the group 2 to prevent the stacked layers 6 and 7 from tipping over.

Upon completion of the group 2 of products 3, which in the case illustrated by way of an example is composed of four layers 6, 7, a second pusher 19 transfers the group 2 from the grouping station 5, in the feed direction V, to the packaging station 23 where the packing means 8 package the group 2 in the pack 9, as illustrated in FIG. 6.

More specifically, the group 2 of products 3 moves translationally along the first or second profiled sections 14 a and 14 b from the grouping station to the packaging station 23.

This invention also relates to a product packaging method comprising a step of conveying the products 3 along a feed axis D in a feed direction V, a step of grouping the products 3 in a group 2 of products 3 comprising at least a first and a second layer 6 and 7 of products 3 and a step of packing the group 2 of products 3 to package the selfsame group 2 into a pack 9.

The step of grouping the products 3 comprises a step of stacking a layer 6, received later, under one or more layers 6, 7, received earlier, to form the required group 2 of products 3.

More specifically, the grouping step comprises a step of stacking the first and the second layer 6 and 7 from the bottom up.

The stacking step comprises a step of forming the first layer 6 and raising at least the first layer 6 from the bottom up and a step of retaining the first layer 6 in the raised position.

During the step of retaining the first layer 6 in the raised position, the method comprises a step of forming the second layer 7 and releasing the first layer 6 onto the second layer 7 thereby stacking them.

It should be noted that the steps of forming the first layer 6, raising at least the first layer 6 from the bottom up and holding it in the raised position during the step of forming the second layer 7, and of releasing the first, raised layer 6 onto the second layer 7, thereby stacking them, are repeated in sequence until obtaining a group 2 of products 3 comprising a defined number of layers 6, 7.

The method comprises a step of raising the second layer 7 from the bottom up and the step of releasing the first layer 6 onto the second layer 7 occurs during the step of raising the second layer 7 from the bottom up.

Advantageously, the machine 1 is more versatile compared to the prior art since the stacking means 11 allow forming groups 2 of products 3 composed of a potentially variable number of layers 6, 7, since there are no physical limits on stacking due to the dimensions of the machine 1.

Moreover, the simultaneous rotation of the first and second arms 15, 16 about the first hinge C1 located at the same first end 15 a, 16 a allows the machine 1 to operate at higher speeds. 

What is claimed is:
 1. A product packaging machine comprising a conveyor (4) for feeding the products (3) in sequence; a grouping station (5) for the products (3) received in sequence from the conveyor (4), for grouping the products (3) into a group (2) of products (3); each group (2) comprises at least a first and a second layer (6, 7), each layer (6, 7) comprising one or more of the products (3) and being positioned one on top of the other; the packaging machine (1) comprising means (8) for packing the groups (2) of products (3) to package the group (2) of products (3) in a respective pack (9), and comprising, at the grouping station (5), stacking means (11) which are designed to stack relative to a stacking axis (A) a layer (6), received later, under one or more layers (6, 7), received earlier, to form the required group (2) of products (3); characterized in that the stacking means (11) comprise a first and a second pair (26, 27) of arms (15, 16), located on opposite sides of the stacking axis (A) and each comprising at least a first and a second arm (15, 16); the first and the second arm (15, 16) of each pair (26, 27) are connected to the same first hinge (C1) located at the same first end (15 a, 16 a) of the first and the second arm (15, 16).
 2. The machine according to claim 1, wherein the first and the second arm (15, 16) of each pair (26, 27) comprise a respective first and second profiled section (14 a, 14 b) for supporting the first and second layers (6, 7) of products (3), each connected at a respective second end (15 b, 16 b) of the first and the second arm (15, 16), opposite the first end (15 a, 16 a), by means of a respective second hinge (C2); the second hinge (C2) of each first and second profiled section (14 a, 14 b) allows the first and the second profiled section (14 a, 14 b) to rotate independently of the rotation of the arms (15, 16) about the first hinge (C1).
 3. The machine according to claim 1 or 2, wherein the first and the second profiled section (14 a, 14 b) of each pair (26, 27) of arms (15, 16) rotates about the respective second hinge (C2) in a direction of rotation opposite to the direction of rotation of the respective first and second arm (15, 16) about the first hinge (C1).
 4. The machine according to claim 2 or 3, wherein the first and the second profiled section (14 a, 14 b) of each pair (26, 27) of arms (15, 16) maintains its position while the layers (6, 7) of products (3) are being stacked relative to the stacking axis (A).
 5. The machine according to any one of claims 2 to 4, wherein the first and the second profiled section (14 a, 14 b) of each pair (26, 27) of arms (15, 16) comprises a respective flat surface (17) for supporting the layers (6, 7) of products (3) and parallel to the underside contact face (25) of the layers (6, 7) of products (3); the flat supporting surface (17) remaining parallel to the underside contact face (25) of the layers (6, 7) of products (3) while the layers (6, 7) of products (3) are being stacked relative to the stacking axis (A).
 6. The machine according to any one of claims 2 to 5, wherein the first and the second profiled section (14 a, 14 b) of each pair (26, 27) of arms (15, 16) rotates about the second hinge (C2) simultaneously with the rotation of the first and second arm (15, 16) about the respective first hinge (C1).
 7. The machine according to any one of claims 2 to 6, wherein the first arm (15) and the first profiled section (14 a) and the second arm (16) and the second profiled section (14 b) of each pair (26, 27) constitute first and second retaining elements (12, 13) which move alternatingly from a first to a second operating position, raising one of either the first or the second layer (6, 7) from the bottom up; at the first operating position, the first and the second retaining elements (12, 13) alternately supporting at least one of either the first or the second layer (6, 7) of products (3); at the second operating position, the first and the second retaining elements (12, 13) alternately supporting one or more layers (6, 7) of products (3) received later than the layers (6, 7) received earlier in the first operating position, until the group (2) of products (3) is completed.
 8. The machine according to claim 8, wherein the first and the second retaining elements (12, 13) are coordinated with each other in such a way that the first retaining elements (12) move from the first to the second operating position while the second retaining elements (13) simultaneously move from the second to the first operating position, and vice versa.
 9. The machine according to any one of claims 1 to 8, wherein the first and the second arm (15, 16) of each pair (26, 27) rotate about the first hinge (C1) by a respective quantity equal to the size of the angle of rotation (α1, α2); from the first to the second operating position, and vice versa, the size of the angle of rotation (α1, α2) of the first arm (15) being different from the size of the angle of rotation (α1, α2) of the second arm (16). 